This disclosure relates to variable resistance strut assemblies and articles that contain the same.
Strut assemblies are often used in automobiles to facilitate the opening, locking and positioning of doors, trunks, hoods, tail-gates, or the like. These assemblies generally do not offer opportunities for fine control. In addition, these assemblies are often susceptible to temperature changes and their performance tends to vary with temperature and other environmental conditions. The strut assemblies that are commerically available have functional attributes that are fixed during design and manufacture. These functional attributes cannot be controlled but can vary with wear and operating conditions. For example, the fluid used in a strut assembly may have a viscosity that is chosen to yield optimum performance in terms of the effort required to extend and retract the strut over a nominal range of temperatures. If however, the temperature drops below this nominal range, the viscosity increases, thereby increasing the effort required to extend and retract the strut.
It is therefore desirable to use strut assemblies that offer opportunities for fine control during opening and closing and which offer reproducible performance under a variety of different conditions.